I followed Dave’s instructions for Going Crazy with Macros and I can see there is some real power in building up macros to customize your blog. The Radio Userland pages don’t seem to provide many more details, though. Is there a “Programming your Radio Userland Blog” page that I haven’t found yet?
Answering my own question, it looks like http://radio.userland.com/faq leading to http://radio.userland.com/directory/6742/documentation are good places to start. Ok, back to reading and learning…